The Effect of Sc on the Biocorrosion Properties of Selected Zinc-Based Biomaterials

In this study, Zn-based alloys were produced by the conventional casting technique. After homogenization heat treatment, microstructural properties and corrosion life of pure zinc, Zn-Mg, Zn-Mg-Al, and Zn-Mg-Al-Sc alloys were investigated. Effects of additional elements, heat treatment, and phases formed in the structures affecting corrosion resistance were systematically investigated. To evaluate corrosion, we performed electrochemical and immersion tests in Hank's salt solution. Corrosion resistance deteriorated in scandium-added Zn-Mg-Al-Sc alloys due to localized galvanic coupling, whereas we observed improvements in microstructure. On a positive note, the Zn-Mg-Al alloy showed the best corrosion resistance. Our findings on the microstructural changes and corrosion resistance effects of Sc addition to biodegradable Zn-based alloys helped to explain the complex role played by Sc. The previous studies focused mostly on binary and ternary systems of Zn alloys. However, new insight into the role of Sc adding in Zn-based alloys is contributed by this study. The findings of our study clarify the effect of Sc on the microstructure and bio-corrosion behavior of Zn-based alloys. As a result, more reliable biodegradable Zn-based alloys will be designed thanks to this study.